Electric circulation water-heater.



J; I. AYER.

ELECTRIC GIRGULATION WATER HEATER.

APPLICATION FILED JULY '1, 1908.

PatentsdDec. 13, 1910,

8 5 i I g l i 1 x UNITE STATES PATENT OFFICE.

JAMES I. AYER, OF CAMBRIDGE, MASSACHUSETTS, ASSIGNOB TO SIMPLEX ELECTRIC HEATING" COMPANY, OF BOSTON,-M.ASSACHUSETTS, A CORPORATION OF MASSA- My invent-ion has for its object the pro- -vision of a compact .and efficientelectrical heater for heating water in a boileror tank such for instance as the usual household hot water boiler or kitchen tank. My

heaterheats the water in the tank by circur lation, the water passing out of the bottom of the tank, up through theheater and back intotheltl nk,

.constructional details of my invention willbe pointed out more at length in the course-0f the following description, ref- Terence-be hadto'the-accompanying draw- .ing's,*-in w ich I have shown a preferred embodiment .of the invention.

In the' dra'wings.; Figure 1 shows in side elevation my invention in operative completeness {Egg} 2 is a longitudinal sectional view of the'heater proper; and Fig. 3 is a diagrammatic. view showing the electrical wiring and connections.

The boilerI may be of any usual or preferred kind, being herein shown .as of the closed ,type having a circulation inlet pipe 2, an out et pipe 3, and a hot water service pipe 4. Connected to the outlet pipe 3, I

provide a oirculation'pipe 5 which extends upwardly-and has. connection at its upper end with the top of .the boiler, either 'rectly to the hotlwater service pipe 4 as indicated at 6 or to. the top portion of the boiler as indicated by dotted lines 7, the latter construction being used with an open top boiler. I interpose ln-i1lllS branch circulation system 5,-6, my heater indicated in Fig. l-at 8 and shown in detail in Fig.2. Re-

ferringto Fig. 2, it will be seen that I provide similar end castings 9, 10, threaded at 11 on the opposite ,ends of a steel tube and preferably both provided with a. checking plate'13 having a small orifice M herein shown as a-singl'e-openiug and centrally located, the idea being to choke or check the free flow of the water compelling it to cir- ELECTRIG CIRCIJ'LATION. WATER-HEATER will be seen thatthe casting 10 has an externally threaded vnipple 15 against whose inner conical surface 16 a similarly clinically shaped end 17 of the pipe 5 is tightly" clamped by a threaded nut 18 whose inner? Specification of Letters Patent. Patented 1343c, 13, 1910. Application filed July 7 1908. Serial No. 442,310.

shoulder 19 engages an externalshoulder 20- of the pipe. The orifice 14 opens into a preferably enlarged chamber 21- and thence the water passes directly into the tube 12.

Resistance conductor wire is embedded in a.

coating 22 of vitreous enamel or other suitusual manner on the pipe .12, four terminal plates 23, 24, 25, 26, being embedded in said enamel so as to protrude from the; enamel at equidistant points, and the windin is connected to said terminals and divide thereby into three sections 27, 28, 29. Circuit wires 30, 31, 32, are then connected as shown clearly in the. diagrammatic Fig. 3. An external pipe 33 preferably .of brass surrounds the whole, preferably resting on a ledge 34 formed at the lower edge of a flange 35. of the casting 10 to which the tube or jacket 33 is secured preferably by screws 36, the

37 to a similar flange 38 on the upper casting 9. j The tube or jacket 33 is lined witha close fitting layer 39 of'asbestos to prevent heat-loss through the walls' ofthe shell or able insulating material which is fused in upper end of "said jacket being secured at.

jacket, and between this outer .covering and T the inner tube and its winding, is a closed air space which limits to a minimumthe loss of heat by conductionor radiation in an outward direction. The tube or acket 33 has a slot 40 in its lower end in which a porcelain bushing 41 is placed, being provided with a peripheral groove 42 for the purpose of engaging the walls of said slot to hold it firmly. This bushing has a smooth central opening 43 through which the wires 3032 pass and thence are led to a switch at, 4.5. In practice, I employ a well known .type of plug switch, but' for the purpose of clear description andundcrstanding, I have simply typified the switch and its movements, the line wires being indicated at 46, 47.

. the top portion ogly'qr small. nion M nister in the to I J theta From the foregoingdescription; it will be readily uIulcrstogxi'thatas the water is heatil and nece sarily uses, it flows upwardly through the heater and thence throu h the this circulation is kept up continuously so that the entire contents of the boiler is heated gradually from the top downward, and afterwardmaintained hot at comparatively small cx wuditure. If it is desired to heat the water quickly, the switch is turned to throw all the resistance wire of the three section into multi 1e closed circuit, whereas a more moderate eating is obtained by cutting into seryice one or two sections only. By'thc provision of the resistance wire orran (1 in u series'of sections along the height of t e elongated vertical to and arranged so'that heating currentt can diverted to l 0 all of said tube at option, t is'possi lg! to very quickly heat the r t. i l so. 1 N9 3 "I it t e wh l whee-chat be we c tents'thereof will be heated in a longer period. I In this connection it should be under pipe 12,'the water is quickly hcat'ed, but, be-

cause of the choked orifice 14-attheuppcr end of the heater, the water is held'fin the heater until it has absorbed considerable heat and zit-length forccs its way upward on up colijlltof its e'xpansion.

principal P nteare' tome-o ossum lZ.1 2. l@ great advantage of my cou- 'sli'llctlon m heath: the. water Wlil! a lllilXh mum lh n y mu minimum current, and

second, the i l' antag of heating the water to a h gh (numeral-um before it. escapes ,totho boiler. I u regard to the first point, by pro viding: he cuameh mlmhlod wu'o dircctly on thc tub It! t c h alcr is brought within the shortest pvaot icahlo conducting distance (mm the water and the water is hrought in direct heat is so rapidly taken away from the tubeby the direct c ntact thcrcwith of the water,

c auses the external surfacc of the eiunnelcd tube is always at a relatively low icmpc-raturc. as compared with that, which it won-id} have it the resistance-carrying n'ugdgiaun wow not in dlrect contact withthe c, vuliating water. In regard to the second point; by choking the ivaterf a p toxidinna small orifice m the top and b0tt9irl, a much higher tempera ture of water-delivery is insured, or in other words, the circulation begins with a temperature many degrees higher than if the "opening were the full size of the circulation tarding, tic-vices dcsorilmd, consisting of "t'lm g P 13 with the siuall orifices 14 l therein, maintain a slow continuous circulation of watcr through the heating tube-at a loss speed than would otherwise be natural through said tube and the rest of the circulation piping. and hence deliver without disturbance to the rest of the tank. contents a gl'aduul acculmllation of highiv heated wator at the top of the tank which is hvailable for use without waiting for tlupcntire contents of tho-tank tobe lu'flitthi I take advantage of tliewell known fact that hot water is rcry slow to mingle downward with cold water below it, and'hence by retarding the delivery of the but water until it has been brought by my heater 'to a high temperatnrc, and then by depositing this highly catcd Water on the top of the relatively cold water ill the tank, it remains there without appreciably aii'eoting or being affected by the water below. with the result that my heater will permit the user to draw from the tank. after uhout a fcw'minutos a )plica tion of the heat. water ,at 180 F. i regard this feature of providing means for limiting thero-tc of circulation or roducing slow circifi lotion as particularly-important and advan vtilgcml's. Having the heater in thc' formof a tubular heatmg section surrounding a portion of the circulation pipe is advantageous as it confines theheat radiation thereof in such a manner as to impart heat with the greatest cfiiciency to the water passing thercthrough. As thehot water escapes n into the pipe 6 and thence back into the oiler. more cold water goes in at the bottom, and this circulation is maintained continuously.

It will be obvious to'those'skilled in the art that many changes, substitutions and rcarrangement of paits may lie rcsortcd to within the spirit and scope of my invcntion means providing a tubular circulation (nurse forthe continnous'flow of the water to be lieated,;-a heat ng section-and means, including'a water pipe, a transverse check plate be natural to the cireulation course.

a 36 re s momen tidn for conducti at the end-of ,saidpipe and of said heating section having a small orifice'smaller than the cross section of said-pipe, for producing a slow flow of the water at said heating sectiomyoffless speed than would otherwise 2. A circulation water heater,- comprising means providing atubular cllosqdaaircuitcirculgi tion course forith'e cdntitaious re ated new of the vaterto. be heaoed,'inclu' ing a heating section presentingan extehded =heatin'g' area with which the watermust come in direct contact asit flovvs throu h its course, meansatthe he'ater inclu ng a Water. ipe, a chec plate at the endo said pipe andoZ- said eating sec: tion having, a small orifioe' -sina-llerfthan the Ipe, for retarding the li e in? centre, nt rS- d he area, and heating 'fli'dunted on said sec Y electric currentto maini mes e hea d t $3 Ajimalatioa Water. heater,- having at posits ends fprrecelvmga water itaop Q J spectivetg, and provided intermediate said ends wi a tubular passage. for containing the water to be-lieated, anda choked passage at the outlet end smaller than the discharge pipeand than said tubular pas-- sage forretarding the of said water from said, tubular passage and-increasing the interval theaWater-is retained insaid tubular .wat e r therein.

passe electric heating means surg said tubular passagefor heating 1 1k circul' tion vvater heater, comprising. meansp vigling a tubular circulation course fQfZthe continuous flow of the water to be heated, includinga heatin'g sect-ion', containbig electric-heating. means, and means for retainin the'vvater in a comparatively sluggishly owing conditio'n within said section,

including at the inlet end of the sec- 'tion' for retardin% the passage of Iwater thereat rection,- and means at in either -th'e outlet end of the section for retarding theputward escape of the heated water from saidjsecti'on eta less speed than the otherwise mealt mer the water in its course beyond said section.

5. A circulation vwater heater, comprising circulation piping, a tube interposed therein, electric resistance medium mounted about pipeand water discharge Pipe 8, tube, resistance current-. d mounted chamber and pipe water to said chamber, S31 greater diameter than salad tube, a check said tube for heating the latter, divided into a plurality of sections. switchingmeans for-directing the current through a art or through all of said-sectionsas and retarding meahs independent of said tube. and of said piping-cooperating with said tube'and said heatin means for niainesired,

tainin g a slow continuous circulation of water through said tube when thecurrent is turned on,a;-t less speed than would otherwise be uatural't-hrough said tube and the restof said circulation piping. v

6: A water 'heater, comprising a tube adapted to be \"ertioallyarranged in use a water supply to the bottom and awater elivery from the top thereof, a resistance curheight' of said tube and having terminals at 'itstop and bottom and also intermediate the height thereof, and connections, including a switch, for directing current. selectively rent conductor extending substantially thethrough said terminals to a ply heat toa selected part or all of said tu 'atoption.

7.'A water heater comprising a tube adapted to be vertica 1y arran ed in use, a

vater supply tothe an a water dc- ,llvery from the top thereof, a resistance curthereon for heatin the tube, .a jacket inclos-.- in said tube and eating conductor'to provi e-an insulating air space about the same,

means at the outgoing end of said'tube providing an enlarged chamber independent of s id air space and larger in diameter than.

said tube, 'a discharge pipe leading from Said-chamber, and a check plate between said provided with an orifice smaller than said-pipe through which the water dischargedfrom said tube into said chamber must pass from the chamber intosaid discharge pipe,.'sai'd chamber being closed water-tight excepting for said orifice and tube.

9. A circulation watenheater, comprising,

a tube, resistance cur-rent-condtibt'tn. mounted thereon for heating the tube, a jacket inclosing said tube and heating conductor to pro- 4 vide'an insulatingair space about the same,

means at the ingoing end of said tube providing an enlarged chamber independent ,of said air space, an inlet pi e for .admitting chamber having plate betwee'nsaid pi eand said chamber dis provided with an, ori ce smaller than thepipe through which the water must pass from said pipe to said chamber, 1110:1118 at: the outgoing end of stud tube providing an enlarged chamber independentof said air sauce 21 (limluu' e Eipe leading from said niiaer, and a e lee plate between said (llS- tween sai ehax nhe i sfbeing through said u e. '-10. A 'w'ater heater, comprising a tube,

means for appllying heat thereto, and a cap fittedto men thereof, said'caphavin an inwardly. directed flange with a restricted opening therethrough, and a conneetion for 20% tax, sai flange opening bein'gfmaterially.

reeeivin a water conductor adjacent theresmaller than the cross section of any other part of the eircnlatonv system.

11. A. water heater, comprising a tube,

means for applying heat thereto, and a cap fitted to an end thereof, said cap havm an inwardly directed flange with a restricted;

opening therethrough, ii-connection for recelving a water conductor ad acent thereto,

,said flange opening being materially smaller than the cross section of any other part of the circulatory system, and an external .fiange for supportingan external jacket spaoed'aparti from said tube.

In testimony whereof, I have signed niy 35 name to this specification, in the presenceof. two subscribing witnesses. I

" 'J'AS. I.

\Vitnesses:

EmzABE'rmM. COUILIN, Dona A. Pnoo'non. 

